From "Tunnellers": The Tunnellers request that the Fantasia provide musical entertainment. Lilith offers to sing. The Fantasia's reaction reeks of Oh Crap. Garland even lampshades this, remembering that the Tunnellers' supposed abilities.
Garland: I thought they were supposed to have good hearing?
Meta-example: in "Laketown" Goneril catches Maska in one of their caravans while holding baby Jewel in her arms. When she yells "GET OUT!" at the top of her lungs the baby actress jumps and looks up at her with obvious confusion as to why the nice lady has suddenly raised her voice.